EFFECT OF VITAMIN K3 ON CHICKEN PRODUCTION PERFORMANCE AND BONE QUALITY 1-LATE PHASE OF EGG PRODUCTION

Department of poultry breeding, Animal Production Research Institute. A.R.C

Abstract

The present study was designed to study the direct influence of supplementing of layers diet at late phase of egg production and housed in cages with high levels of vitamin K3 on productive performance, eggshell parameters, tibia bone composition and histological observation, hatching traits and some blood parameters. One hundred and fifty Mandarah chicken females with thirty males were individually housed in cages from 55 up to 67 weeks of age. The birds were randomly divided into 5 groups representing the dietary supplementation. The birds of the first group was served as control (T1) without any supplementation and fed diet contains 3 mg menadion (K3) / kg diet . The rest 4 groups were supplemented with menadion as additional doses of vitamin K3 source to be 7, 11,15 and 19mg menadion / kg diet for T2, T3, T4 and T5 groups respectively. Obtained results revealed that hens of T3, T4 and T5 groups represented significantly (P≤ 0.05) produced larger eggs , besides all supplemented groups represented highest (P≤ 0.05) egg mass and egg production% compared to those for control group (T1).Also, highest values of shell thickness (mm) and Ca% in eggshell were detected for eggs of T3 and T4 groups compared to the rest groups. Moreover, the best improvement of tibia measurements (length , width and breaking strength) and composition (weight, ash%,Ca% and P%) were recorded for hens T3 and T4 groups. Eggs produced from all supplemented groups represented significant increase of fertility and hatchability of fertile egg percentages compared to those for control one. Birds of the T3 groups recorded the highest values of the serum osteocalcin and plasma Ca, ICa, P and alkaline phosphatase. Histological observations of tibia bone for birds of T3, T4 and T5 groups illustrate the increase of medullary bone, thick outer cortical layer and osteoblasts cell activity. In conclusion, supplementing the layer diet at late phase of production and housed in cages with either 11 or 15 mg vitamin K3 / kg diet could be a promising tool for realizing the best improvement of egg production, shell and bone quality and hatchability%.